1. Field of the Invention
This invention relates to telephonic communications in which a telephone system is combined with a diverse electrical system for signalling purposes, more specifically it pertains to remote command, control and monitoring of a plurality of fixed site independent operating systems such as public utility electric, gas and water meters, by way of an existing commercial paging service network.
2. Description of the Prior Art
Most electric, gas and water meters are read by a utility service provider person who visits each meter site. Alternatively, a large user site such as a manufacturing plant may be wired by a telephone line to the utility.
The majority of meters are in residences, stores, and small business facilities. Taking the readings is costly, time consuming, and sometimes hazardous from weather and from entering upon private properties. Not all regularly scheduled readings can be taken.
One improved system has the meter in the building wired to a plug in a box mounted outside the building so that the visiting meter reader can plug a hand-held computer into the box to obtain a reading from the meter.
Another improved system adds a low powered transmitter to the meter so that the visiting meter reader obtains each reading by driving past the site.
If the utility service provider wishes to provide information to the user, and provide command or control service of the user site, additional difficulty and cost is incurred.
A utility may wish to inform a site of an impending change in electrical voltage or price rate, a safety alert, security breach, or end of service warning in pay-before-use arrangements.
The utility may wish to command a computer to read meters in an apartment building, and store it for a single quick read, or to transmit it in a single burst in a subsequent polling of sites, or to disconnect, reconnect and/or regulate service, shed load, prompt selected alarms, or remotely control user equipment to operate when demand on the utility is low, to provide a lower price rate.
For reliability and safety, a site should be able to initiate transmission of information to the utility to report an unexpected situation which requires attention by the utility, and to report to the utility upon demand by the utility.
Providers of the above services need a system which provides low cost two-way transmission and reception between the utility and individual sites and between the utility and groups of sites, with little delay between the need for a communication and its accomplishment.
Present remote monitoring systems primarily use the public telephone network, unlicensed radio and proprietary fixed and licensed radio systems.
Wherein the heaviest of two-way communication with a site may only require bursts of from a fraction of a second to a few seconds long, minutes, hours or days apart, this is costly for each communication and/or each site because of initial investment in equipment, or because tariffs are intended for continuous use of the communication network or medium.
The time that a communications network is utilized for remote command, control and monitoring (RCC&M) is short relative to most other uses for the network because RCC&M message lengths are brief with long idle periods. It is presently costly to remotely control and monitor many sites by way of existing communications networks.
Cable and cellular system pricing structures are relatively costly for meter reading requirements. Other systems such as communicating over power lines carry their own additional costs.
It is not practical to invest more than a few hundred dollars on a residential site to bring it onto a remote command/control and monitoring system because revenue from a residential or a small business site is relatively small compared to total revenue from all sites.
Since more than eighty-five percent of meters are attached to residences, it is no wonder that only a small percentage of all meters and related sites have been instrumented for one or two-way communication.
In FIG. 1, PRIOR ART commercial paging service network 20 is accessed by telephone 26 by which a message of instruction is sent to central controller 30 for processing by an area transponder 46 for transmission by antenna cluster 34 to a particular one of pagers 36 by the paging network.
Each pager has its own unique address ID code AB12, BC14, FA12, EA19, DB16, or EB17. The message called in to the central controller over the telephone includes the address ID code of the pager. The message also may include the instruction or command of what action is to be taken by the pager, such as display a telephone number or other alphanumeric display. The message may include a command originated by the telephone caller or by the central controller, that the pager transmits back an acknowledgment code.
The central controller converts the message into a transmission code that is easily transmitted by area transponder 46 by way of the antenna cluster, and is easily decoded by the pager.
The pager is a small portable transceiver carried on-person by the paging service subscriber. Consequently, a pager is carried in and out of the transmission range of one or more antenna clusters of the paging service network. Since the whereabouts of a particular pager is unknown to the paging service at the time of initiation of a message transmission by the central controller 30, all area transponders 46 simultaneously transmit location request bursts of the pager address ID code of the desired pager on all antenna clusters.
All pagers in transmission range of the antenna clusters receive the call. Upon receipt of a burst of a particular pager's ID address code from all antennas of a paging network that are within receiving range, the particular pager addressed sends back an acknowledgment burst as a notice that the broadcast burst was received. All other pagers remain silent.
In response to the acknowledgment burst from the pager, only the paging network transmitting antenna which is approximately closest to the responding pager continues to communicate with the pager for as long as it is necessary for the immediate communication.
Typically, the location request burst and response burst are transmitted on a separate frequency channel from the message transmission channel. This allows a message to be sent to the alerted pager without alerting the remaining pagers in the area of the transmitting antenna cluster.
The paging network does not transmit to any of the remaining pagers unless it receives another message designating one of the pager address ID codes from one of the remaining pagers.
This procedure frees up the other paging network transmitting antennas for communication on the same frequency with other pagers.
In FIG. 2, PRIOR ART commercial pager 250 is similar to ones in the prior art for communication with a pager service. It includes RF transceiver 252, and digital signal processor 254 which processes information from controller 256 for transmission, or processes information from the transceiver for the controller.
In a more advanced prior art pager such as pager 250, an RS 232 communication port 262 is provided. Port 262 is connected to the controller so that information can be communicated to and from an external device 264 RS232 communication port by way of the pager.
Battery 258 provides power for power supply 260.
List A shows the advantages and disadvantages of various communication systems for two-way command, control and monitoring of a residential or small manufacturing site, compared to the present invention system.
In the list,
(1)=sharing a telephone line with the site owner PA1 (2)=two-way communication initiated by the site device PA1 (3)=two-way communication initiated by the utility company, requires a telephone line at the utility site and special service by the telephone carrier to establish communication with the site device without disturbing the site telephone subscriber.
__________________________________________________________________________ LIST A: Shared (1) telephone Invention Power in out Radio pager System features line cable (2) (3) fixed mobile system __________________________________________________________________________ Avoid high equipment no yes yes yes no no yes investment, including radio licenses Is practical when not no yes yes no no no yes many sites are in the area Competition between NA no yes no NA NA yes communication systems, encourages low tariffs Service to site is un- no no no no yes yes yes affected by disconnect of the wired services Brief two-way trans- NA no yes no no NA yes mission between long periods results in low total tariffs Brief two-way trans- NA no no no no NA yes missions between brief periods results in low total tariffs Negligible wait to in- yes yes no no yes no yes itiate a communication Communication is un- yes yes no no yes no yes affected by other users Has broadcast and yes yes no no yes no yes polling capabilities Available at all times yes yes yes yes yes no yes Communications can be yes yes yes no yes no yes initiated by site device or by the utility __________________________________________________________________________